Friday, January 30, 2015

Why are methane concentrations in the atmosphere over the Arctic Ocean so high from October through to March?

The image below, replotted by Leonid Yurganov from a study by Chepurin et al, shows sea water temperature at different depths in the Barents Sea.

Above image illustrates that, while Arctic sea water at the surface reaches its highest temperatures in the months from July to September, water at greater depth reaches its highest temperature in the months from October to March. Accordingly, huge amounts of methane are starting to get released from the Arctic Ocean's seafloor in October.

Surface temperatures in October

As the image below shows, temperature at 2 meters was below 0°C (32°F, i.e. the temperature at which water freezes) over most of the Arctic Ocean on October 26, 2014. The Arctic was over 6°F (3.34°C) warmer than average, and at places was up to 20°C (36°F) warmer than average.

At the same time, continents around the Arctic Ocean are frozen. Surface temperatures over the Arctic Ocean were higher than temperatures on land at the end of October, due to the enormous amounts of heat being transferred from the waters of the Arctic Ocean to the atmosphere. This was the result of ocean heat content, which in 2014 was the highest on record, especially in the Arctic Ocean, which also made that at that time of year the sea ice extent was still minimal in extent and especially in volume.

Start of freezing period

In October, the Arctic Ocean typically freezes over, so less heat will from then on be able to escape to the atmosphere. Sealed off from the atmosphere by sea ice, greater mixing of heat in the water will occur down to the seafloor of the Arctic Ocean.

Less fresh water added to Arctic Ocean

The sea ice also seals the water of the Arctic Ocean off from precipitation, so no more fresh water will be added to the Arctic Ocean due to rain falling or snow melting on the water. In October, temperatures on land around the Arctic Ocean will have fallen below freezing point, so less fresh water will flow from glaciers and rivers into the Arctic Ocean. At that time of year, melting of sea ice has also stopped, so fresh water from melting sea ice is no longer added to the Arctic Ocean either.

Rising salt content

As addition of fresh water ends, the salt content of the water in the Arctic Ocean starts to rise accordingly, while the Gulf Stream continues to push salty water into the Arctic Ocean. The higher salt content of the water makes it easier for ice to melt at the seafloor of the Arctic Ocean. Saltier water causes ice in cracks and passages in sediments at the seafloor of the Arctic Ocean to melt, allowing methane contained in the sediment to escape.

The image on the right, from a study by Hovland et al., shows that hydrates can exist at the end of conduits in the sediment, formed when methane did escape from such hydrates in the past. Heat can travel down such conduits relatively fast, warming up the hydrates and destabilizing them in the process, which can result in huge abrupt releases of methane.

Heat can penetrate cracks and conduits in the seafloor, destabilizing methane held in hydrates and in the form of free gas in the sediments.

Less hydroxyl in atmosphere

Besides heat, open water also transfers more moisture to the air. The greater presence of sea ice from October onward acts as a seal, making that less moisture will evaporate from the water. Less moisture evaporating, together with the change of seasons (i.e. less sunshine) results in lower hydroxyl levels in the atmosphere at the higher latitudes of the Northern Hemisphere, in turn resulting in less methane being broken down in the atmosphere over the Arctic.

Gulf Stream

Malcolm Light writes in this and this earlier posts that the volume transport of the Gulf Stream has increased by three times since the 1940's, due to the rising atmospheric pressure difference set up between the polluted, greenhouse gas rich air above North America and the marine Atlantic Air.

The increasingly heated Gulf Stream with its associated high winds and energy rich weather systems then flows NE to Europe where it is increasingly pummeling Great Britain with catastrophic storms, as also described in this earlier post, which adds that faster winds means more water evaporation, and warmer air holds more water vapor, so this can result in huge rainstorms that can rapidly devastate the integrity of the ice. The image below further illustrates the danger of strong winds over the North Atlantic reaching the Arctic.

Branches of the Gulf Stream then enter the Arctic and disassociate the subsea Arctic methane hydrate seals on subsea and deep high - pressure mantle methane reservoirs below the Eurasian Basin - Laptev Sea transition. This is releasing increasing amounts of methane into the atmosphere where they contribute to anomalously high local temperatures, greater than 20°C above average.

Emissions from North America are - due to the Coriolis effect - moving over areas off the North American coast in the path of the Gulf Stream (see animation on the right).

The Gulf Stream reaches its maximum temperatures off the North American coast in July. It can take almost four months for this heat to travel along the Gulf Coast and reach the Arctic Ocean, i.e. water warmed up off Florida in early July may only reach waters beyond Svalbard by the end of October.

Waters close to Svalbard reached temperatures as high as 63.5°F (17.5°C) on September 1, 2014 (green circle). The image below shows sea surface temperatures only - at greater depths (say about 300 m), the Gulf Stream can push even warmer water through the Greenland Sea than temperatures at the sea surface.

Since the passage west of Svalbard is rather shallow, a lot of this very warm water comes to the surface at that spot, resulting in an anomaly of 11.9°C. The high sea surface temperatures west of Svalbard thus show that the Gulf Stream can carry very warm water (warmer than 17°C) at greater depths and is pushing this underneath the sea ice north of Svalbard.

Through to March the following year, salty and warm water (i.e. warmer than water that is present in the Arctic Ocean) will continue to be carried by the Gulf Stream into the Arctic Ocean, while the sea ice will keep the water sealed off from the atmosphere, so little heat and moisture will be able to be transferred to the atmosphere.

Start of melting period

This situation continues until March, when the sea ice starts to retreat and more hydroxyl starts getting produced in the atmosphere. Increased sea ice melt and glaciers melt, the latter resulting in warmer water flowing into the Arctic Ocean from rivers, will cause salinity levels in the Arctic Ocean to fall, in turn causing methane levels to fall in the atmosphere over the Arctic Ocean. Furthermore, the water traveling along the Gulf Stream and arriving in the Arctic Ocean in March will be relatively cold.

Wednesday, January 28, 2015

The Norwegian Svalbard Islands are located just few hundred miles from the North Pole. It is a unique environment for glaciers: Here glaciers can survive almost at sea level. This means that ice is constantly brushed by thick low-altitude air, which also dumps increasinlgy rain instead of snow.

As a result of high ocean temperatures and of precipitation nowadays falling as rain for months, the melting of these glaciers now occurs 25 times faster than just some years ago.

This also spells bad news for Northern Greenland's low lying glaciers, which will face increasing summertime flash floods as the Arctic Ocean becomes ice free and warms up, and as precipitation falls in the form of rain, rather than snow.

Sea surface temperature of 17.5°C, west of Svalbard
click on image to enlarge

Last summer, for example, sea water west of the Svalbard reached +18C, which is perfect for swimming - but extremely bad for the cold glaciers on shore which mop up the warm moisture and rainfall from the warmed up ocean.

Flash floods falling on glacier soften the compacted snow very rapidly to honeycombed ice that is exceedingly watery and without any internal strength.

Such ice can collapse simply under its own weight and the pulverised watery ice in the basin forms a near frictionless layer of debris.

As the Arctic continues to warm, the temperature difference between the equator and the Arctic declines. This slows down the speed at which the polar vortex and jet streams circumnavigate the globe and results in more wavier jet streams that can enter and even cross the Arctic Ocean and can also descend deep down over the continents, rather than staying between 50 and 60 degrees latitude, where the polar jet streams used to be (as discussed in a recent post).

Such deep descent over continents can cause very low temperatures on land, while at the same time oceans remain warm and are getting warmer, so the temperature difference between land and ocean increases, speeding up the winds between continents. On January 9, 2015, jet streams reached speeds between continents as high as 410 km/h (255 mps), as shown on above image. Also note the jet stream crossing the Arctic Ocean.

Faster winds means more water evaporation, and warmer air holds more water vapor, so this can result in huge rainstorms that can rapidly devastate the integrity of the ice.

[image and text in yellow panels by Sam Carana]

I suspect that climatically-speaking we are currently entering a methane-driven Bøllinger warming state with the Northern Cryosphere now entering a phase of rapid warming and melting of anything frozen (snow, sea ice, permafrost and sea bed methane clathrates).

This will be rapidly followed by a Heindrich Iceberg Calving event when the warmed and wet ice sheet in Greenland gives away to its increased weight (due to excessive melt water accumulation within and beneath the ice sheet).

This dislodges the ice sheet’s top, due to accumulation of “rotten ice” (honeycombed, soft ice with zero internal strength) at the ice sheet’s base and perimeters.

A huge melt water pulse to the ocean ensues with Jōkullhaups and ice debris loading the ocean with vast amounts of cold fresh water.

Within weeks an immense climatological reversal then occurs as the ocean gets loaded up with ice debris and cold water leading to the Last Dryas cooling and to world-wide droughts.

This loading of the ocean with ice and water leads to severe climatic flop, as the ocean and atmosphere cool rapidly and as falling salinity and sea water temperature briefly reverse all of the current Bøllinger warming, until the climatic forcing of the greenhouse gases again takes over the process, in turn leading to a new melt water pulse as another ice sheet or shelf disintegrates by the next warming.

Today’s rapid melt water lake formation in Greenland and the ultra-fast melting of glaciers are suggestive of near imminent deglaciation process in the Arctic.

Germany’s and Japan’s recent decisions to remove all their nuclear reactors from the sea sides may prove their worth sooner than many think in the far more conservative US and UK where “glacial speed” still means “eons of time”. Good luck UK/US!

I think cold 'Dryases' are not real Ice Ages, but hiatuses in a progressive melting process which results from changes in sea water salinity and temperature due to increases of meltwater and ice debris runoff from continental snow and ice that melt. As ocean gets less saline and colder the sea ice and snow cover temporarily grows.

But in the long run the greenhouse gas forcing and ocean wins and the warmth and melting resumes until the next big collapse of ice shelf and/or ice sheet. Hence there are meltwater pulses (such as 1a, 1b, 1c) and Heindrich Ice Berg Calving surges (2, 1, 0 - the last one being also called "Younger Dryas" as the Arctic Dryas octopetala grew in South once again after Ice Ages).

The next cooling from collapse of Greenland ice dome would be Heindrich Minus One as the zero has already been allocated to Younger Dryas ice berg surge. Here is an article worth reading on this risk. In Antarctica we see currently (already) a sea ice growth hiatus driven by increased runoff of melt water and ice debris from the continent and its surrounding ice shelves that are rapidly disintegrating.

Abrupt climate change happened in just one year

A 2008 study by Achim Brauer et al. of lake sediments concluded that abrupt increase in storminess during the autumn to spring seasons, occurring from one year to the next at 12,679 yr BP. This caused abrupt change in the North Atlantic westerlies towards a stronger and more zonal jet, leading to deglaciation.

A 2009 study by Jostein Bakke et al. confirmed that increased flux of fresh meltwater to the ocean repeatedly resulted in the formation of more extensive sea ice that pushed the jet south once more, thus re-establishing the stadial state. Rapid oscillations took place until the system finally switched to the interglacial state at the onset of the Holocene.

Monday, January 19, 2015

The year 2014 was the warmest year across global land and ocean surfaces since records began in 1880, writes NOAA, adding the graph below. This graph illustrates that temperatures have risen even when focusing on a relatively short recent period with a linear trendline starting in 1998, which was an El Niño year, whereas 2014 wasn't.

While the purple 1998-2014 trendline serves the useful purpose of dispelling the myth that warming had halted recently, it isn't the most appropriate trendline, since extending this trendline backward to 1880 would leave too many data too remote from the trendline, as is further illustrated by the animated image below.

What about the blue linear trendline that is based on data for all the years from 1880 to 2014? By that same logic, the appropriateness of this trendline must also be questioned. Temperatures in recent years have been well above this trendline. A polynomial trendline seems a much better fit, as illustrated by the image below.

Above image also extends the trendline forward, showing that 2 degrees Celsius warming looks set to be exceeded in 2038, based on the same data.

And while this is a frightening scenario, the picture may well be much too optimistic, because the heat is felt most in the Arctic Ocean, the very location where some of the most terrifying feedbacks are accelerating local warming, as further explained below.

Feedbacks in the Arctic

As NOAA writes, much of the record warmth for the globe can be attributed to record warmth in the global oceans, which reached the highest temperature among all years in the 1880–2014 record.

As above image shows, ocean heat reached a record high in 2014. In other words, it was ocean heat that pushed the combined ocean and land temperature to a record high. Anomalies were especially high in the Arctic Ocean, as illustrated by the image below.

Waters close to Svalbard reached temperatures as high as 63.5°F (17.5°C) on September 1, 2014 (green circle). Note that the image below shows sea surface temperatures only. At greater depths (say about 300 m), the Gulf Stream is pushing even warmer water through the Greenland Sea than temperatures at the sea surface.

Since the passage west of Svalbard is rather shallow, a lot of this very warm water comes to the surface at that spot, resulting in an anomaly of 11.9°C. The high sea surface temperatures west of Svalbard thus show that the Gulf Stream can carry very warm water (warmer than 17°C) at greater depths and is pushing this underneath the sea ice north of Svalbard.

Planetary imbalance now is 0.6 W/m2. This has made the rise in ocean heat (up to 2000 m deep) more than double over the past decade. Data from 2005 through to 2014 contain a polynomial trendline that points at a similar rise by 2017, followed by an even steeper rise.

What could cause such non-linear rise?

The answer is feedbacks. Arctic snow and ice loss alone may well cause over 2 W/m2 warming, warns Prof. Peter Wadhams. Another such feedback is methane erupting from the ocean floor, as methane hydrates get destabilized due to higher temperatures.

As illustrated by the graph below, most of this excess heat is absorbed by oceans and ice. Some of the heat is consumed by the process of melting ice into water, and 93.4% of this excess heat ends up warming up the oceans.

As the Gulf Stream keeps carrying ever warmer water into the Arctic Ocean, methane gets released in large quantities, as illustrated in the images below showing high methane levels over the East Siberian Arctic Shelf (red oval left) and over Baffin Bay (red oval right) with concentrations as high as 2619 ppb.

An exponential trendline based on sea ice volume observations shows that sea ice looks set to disappear in 2019, while disappearance in 2015 is within the margins of a 5% confidence interval, reflecting natural variability. In other words, extreme weather events could cause Arctic sea ice to collapse as early as 2015, with the resulting albedo changes further contributing to the acceleration of warming in the Arctic and causing further methane eruptions from the seafloor of the Arctic Ocean.

click on image to enlarge

As the Arctic continues to warm, the temperature difference between the equator and the Arctic declines, resulting in changes to the jet streams and polar vortex.

One such change is a slowing down of the speed at which the jet streams and polar vortex circumnavigate the globe, as discussed in a recent post.

The image on the right shows that the jet streams on the Northern Hemisphere reached speeds as high as 410 km/h (255 miles per hour) on January 9, 2015. Also note the jet stream crossing the Arctic Ocean, rather than staying between 50 and 60 degrees latitude, where the polar jet streams used to be.

As a result, extreme weather events such as heatwaves and storms can be expected to occur with greater frequency and intensity, as also discussed in a recent post. Heatwaves can heat up the water in the North Atlantic, as it flows into the Arctic Ocean, driven by the Gulf Stream, while heatwaves can also warm up the water in rivers that end up in the Arctic Ocean. Heatwaves can also hit the sea ice in the Arctic Ocean directly, causing rapid sea ice melting, while storms can make the ice break up and be driven out of the Arctic ocean,

Demise of the sea ice and snow cover in the Arctic results in further acceleration of warming, not only due to less sunlight getting reflected back into space, but also due to loss of the buffer that currently absorbs huge amounts of heat as it melts in summer. With the demise of this latent heat buffer, more sunlight will instead go into heating up the water of the Arctic Ocean. For more on the latter, see the page on latent heat.

Above image illustrates some of the self-reinforcing feedback loops that have been highlighted in this and earlier posts. Further feedbacks are pictured in the image below.

Above feedbacks are already pushing the temperature rise in the Arctic through the 2°C guardrail.

Based on existing temperature data, global warming on land looks set to exceed 2°C (3.6°CF) warming by the year 2034, but methane eruptions from the seafloor of the Arctic Ocean could push up global temperature rise even faster, in a runaway global warming scenario.

click to enlarge image

This raises the specter of human extinction. With no action taken, there appears to be a 55% risk that humans will be extinct by the year 2045, while taking little action will only postpone near-term human extinction by a few years. Only with rapid implementation of comprehensive and effective action may we be able to avoid this fate.

Comprehensive and Effective Action

In conclusion, the situation is dire and calls for comprehensive and effective action, as discussed at the Climate Plan blog at climateplan.blogspot.com and as illustrated by the image below.

Tuesday, January 6, 2015

Guy McPherson is convinced that humunity will go extinct soon. Guy estimates that it will happen in 5 to 20 years time.

In the video below, Guy discusses a chain of events causing several degrees warming within a few years time, including failure of the electric grid and subsequent fall in aerosols from fossil fuel burning that now mask warming, and failure to maintain nuclear power plants cooling, causing them to melt down.

These events will cause rapid warming that will accelerate loss of the snow and sea ice in the Arctic and cause massive methane releases from the seafloor of the Arctic Ocean, both adding even further warming.

Such massive warming will result in widespread crop failure and loss of habitat for humans over a timespan of up to 20 years, while events could all unfold in just 5 years time.

In the video below, Guy discusses that we are on the edge of extinction, episode 1.

In the video below, episode 2, Guy describes how large releases of methane from the seafloor of the Arctic Ocean alone could end civilization, as they will cause crop failure on the Northern Hemisphere and subsequent collapse of civilization. This will in turn cause failure of the electric grid, etc., as described above. So, whatever event comes first, it will trigger the other events, resulting in several degrees Celsius warming within years and loss of habitat for humans.

The image below highlights some of the complexities associated with the necessary cuts in emissions, including the impact of aerosols that mask the full wrath of global warming by half. In 2007, the IPCC described aerosols as a negative (cooling) force equal to between -0.5 and -2.5 W m-2. In 2009, Murphy et al suggested an aerosol forcing about -1.5 W m-2, reducing the net climate forcing of the past century by about half. In 2011, Hansen et al, based mainly on analysis of Earth's energy imbalance, derived an aerosol forcing -1.6 ± 0.3 W m-2. [source] As David Spratt points out, this equates to a cooling of about 1.2°C. In other words, abrupt ending of aerosols emissions would result in a temperature rise of about 1.2°C in a matter of weeks.

In the video below, Guy McPherson further discusses the impact of aerosols.

Below, 'Edge of Extinction', episode 3, published on 15 January, 2015, featuring Guy McPherson in a fine moment of comedy! Excerpt from his presentation at Butte College, November 20, 2014, Chico, California.

Below, 'Edge of Extinction', episode 4, published on 21 January, 2015, in which Guy comments on the State of the Union address of January 20, 2015.

Below, 'Edge of Extinction', episode 5, published on 27 Jan 2015, featuring an excerpt from Guy McPherson's interview on Global Research December 12, 2014 on the stages of grief.

Friday, January 2, 2015

The lateral viscosity of the thin Arctic sea ice cover continues to lower. In November just one quarter of the high Arctic Ocean basin above 85° north was covered by a thin this winter's ice. This has now doubled, soon covering two quarters. The ice has been pushed away from Russia towards Canada and to the Fram Strait at phenomenal rates.

Animation by navy.mil showing 30 days of sea ice thickness, up to January 1, 2015

This is increasingly suggesting that the remaining half in front of the Fram Strait will be sucked into the Atlantic Ocean soon. The dark blue ice is newly formed crushed ice behind the North Pole (pack ice). We may well be in course to the first recorded ice free season in the Arctic Ocean. In addition, the rear is pushed from behind Canada to the Beaufort and Chukchi Seas.

Animation by navy.mil showing 30 days of sea ice speed and drift, up to January 1, 2015

We need to act, now. I think we need to monitor this development almost on daily basis. I am curious to see how the ice may behave after the last remainders of the second quarter are sucked into the Atlantic Ocean and the newly forming sea ice will face the force of the Atlantic waves. That could mean extremely highly fractured sea ice across the Russian side by the return of spring 2015 sunlight.

I think we are witnessing a historic transition right now with no ice in the summers.

Videos

Global temperatures are rising fast. In the Arctic, temperatures are rising even faster (interactive charts below and right). For 2010 and 2011, NASA recorded anomalies of over 2°C at higher latitudes (64N to 90N), with anomalies of over 3°C at latitudes 79N and 81N in 2010.

For November 2010, anomalies of 12.5°C were recorded at latitude 71N, longitude -79 (Baffin Island, Canada). At specific moments in time and at specific locations, anomalies can be even more striking. As an example, on January 6, 2011, temperature in Coral Harbour, located at the northwest corner of Hudson Bay in the province of Nunavut, Canada, was 30°C (54°F) above average.